Engine piston and method of packing and lubricating the same



April 6 1926. 1,579,409

T. C. SMlTH ENGINE PISTON AND METHOD 6! PACKING AND LUBRICATING THE SAME Fil'ed August 10. 1922 grwen'ro'z Thomas G Smith Patented Apr. 6, 1926.

UNITED TATES I 579,409 PTE'NT orricn.

mouse 0. sMrrH, or SEATTLE, WASHINGTON.

ENGINE PISTON AND METHOD OF PACKING AND LUBRICATING- THE SAME.

Application filed August-10, 1922. Serial No. 530,848.

To all whom it may concern."

Be it known that L THOMAS 0. SMITH, a citizen of the United States of America, and resident of the city of Seattle, in the county of King and State of Washington, have invented certain new and useful Improvements in Engine Pistons and Methods of Packing and Lubricating the Same, of which the following is a specification.

My invention relates to engine pistons and particularly to the method and means employed whereby the packing andlubricating of the surfaces of the piston which contact with the cylinder is secured.

The object of my invention is to provide means and a method whereby engine pistons may be packed so as-to work at all times tightly and without leakage, and at the same time, to furnish an efiicient lubrication between the piston and cylinder surfaces.

. -My invention consists of the novel means and method employed whereby a compound of such character that it will flow slightly under pressure, is carried in the piston and is fed as necessary to the periphery ofthe-piston'so as to at all times maintain a sealed contact between the piston and the cylinder,

and to provide therefore, a highly eflicient lubrication.

The manner of carrying out my method and a prefered type of means for doing the same is illustrated in the accompanying drawings. I I

Figure 1 is a longitudinal'sectiontaken through a piston constructed in accordance with my inventioni Figure 2 is a transverse section of the same piston taken upon the planes indicated by the broken line 22 of Figure 1.

One of the difliculties found in the opera tion of engines, and particularly of engines of the internal combustion type, is to maintain a tight non-leaking joint between the piston and the cylinder, and to furnish a thoroughly eflicient lubrication between the same surfaces. The improved method which is a part of my present invention consists in providing a storage chamber or cylinder within the piston for the reception of a compound which is of such character that it may bemade to flow under pressure and one which is also an eflicient lubricant, and to providethe piston also with a peripheral groove having communication with a storage chamber in the piston, so that this close contact with the cylinder walls, thus maintaining a tight joint, and the compound being also a lubricant, the cylinder walls are elfecti-vely lubricated.

The exact character of the compound employed may be varied. There are a number of lubricants and lubricating compounds which may be adapted for this purpose. The compound which I consider as being most effective for this purpose is one con sisting of powdered graphite or of graphite mixed with other materials, the same being of such consistency that it will flow from the interior chamber to the peripheral groove. It is evident that other materials and compounds might be employed.

The construction of the piston which I prefer to employ for carrying out my invention is illustrated in the drawings. In these the piston 'is composed of two main sections, an inner or lower section 1 and an upper or outer section 2. These two sections are so constructed and secured together asqso to forma chamber or. cylinder 3 within the piston, which chamber is filled with the packing and lubricating compound. The manner of securing these two sections together as illustrated, is to provide them with complemental threaded surfaces as shown at 12. The lowersection of the piston is provided with a shoulder at 10 against which a series of ports 22 distributed about the periphery of the piston.

Within the cylinder 3 formed in the cap of the piston is placed a follower or floating piston 4. This may also-be provided with a packing ring as 40. It is normally. held pressed towards the piston head by means of springs 5 which'are placed within bores 11 formed in the lower or inner section of the piston. .These, acting upon the compound contained in the chamber 3, tend to cause it to flow through-the ports 22 into the outer or peripheral-groove 20.- At the same time the-mass'of the piston 4 under the reciprocating action of the piston tends to act as a hammer to give the compound a blow at each reciprocation, thus tending to drive it outward so as to keep the peripheral groove at all times filled with the compound.

The head of the piston is provided with a threaded bore containing a plug 6 which may be removed when desired and through which a supply of the compound may be forced into the chamber 3 and the springs 5 compressed Whenever this may be necessary. A charge of the compound in the chamber 3 will last for a long time and it will only he rarely necessary to re-charge the same.

The lower portion of the cap 2 which screws upon the lower section of the piston, preferably extends down to a point somehat below the lower level of the Wrist pin. The bore 7 for the reception of the wrist pin is made through both of the piston sections after the tvvo have been screwed to their final operating position. The \vrist pin, therefore, or rather, the bushing therefor which is pressed into the bore 7. acts as a lock to prevent the possibility ol the two sections of the piston becoming separated.

By the method herein described a tight seal may be secured between the piston and the cylinder Walls. The material employed for this being a highly effieient lubricant, will maintain reciprocation such that there will be no observable Wear of the cylinder Wall. The piston also will n'iaintain a tight fit so that there will be no leakage of gas past the piston. 'lheret'ore, the frictional resistance caused by the movement of the piston in its cylinder Will be reduced and Wear of the piston and cylinder will also be 'minimized. In consequence a long life of both piston and cylinder may be secured While at the same time maintaining a thoroughly eflicient joint between the two.

What I claim as my invention is:

1. An engine piston having a groove in its periphery and a compression grease chamber communicating with said groove, a piston in said chamber and springs acting upon said piston to force the grease towards said groove.

9,. An engine piston having a removable cap forming the outer head of the piston. and a chamber closed by said cap, the piston also having a peripheral packing groove communicating with said chamber and piston rings at each side ol said packing 'roove.

3. Au engine piston comprising a lower and an upper section screwing together and forming between them a compound containing cylinder. a piston fitting said cylinder. the upper of said piston sections having an exterior peripheral groove and channels communicating with the compound containing evlinder. the piston having a Wrist pin bore extending through both sections.

4. An engine piston comprising a lower and an upper section screwing together and 'l orming between them a compound containing cylinder, a piston fitting said cylinder. the upper of said piston sections having an exterior peripheral groove and channels coinmnnicating with the compound containing cylinder the lower of said piston sections having spring receiving bores and springs therein acting upon the piston in the compound containing chamber to force the compound out into the peripheral groove.

Signed at Seattle, King County, Washington. this 4th day'la'l August 1922.

THOMAS C. SMITH. 

